It’s kinda when you go watch a movie, you like to have some popcorn. But from an advertising point of view, this video tries to connect with the clients, making them feel emotions.
Also, being interactive, it gives the chance for the viewer to be a part of the story, and thus, be a part of the product. If you think of it, the video doesn’t promote the buying of the pizza or to make your hunger grow, but it does tell you a story where the pizza and the trademark play an important part, like a protagonist if you like.
You can think of these types of advertising as a way to make the product known, to create a curiosity for it, an expectation, and to see it not as a brand, but as something fun and approachable.